1. Field of the Invention
The present invention relates generally to a fluid damper assembly for use in a vehicle.
2. Description of the Prior Art
Such a fluid damper assembly is disclosed in the U.S. Patent Application 2008/0314706 to Lun which includes a housing defining a main chamber extending along a center axis between a closed end and a rod end. A gas cup is disposed in the main chamber and is slidable along the center axis. The gas cup divides the main chamber of the housing into a gas chamber extending between the closed end and the gas cup and a fluid chamber extending between the gas cup and the rod end. A piston is disposed in the fluid chamber and is axially slidable along the center axis. A piston rod is connected to the piston and extends through the rod end to the exterior of the piston. A fluid seal is disposed annularly about the gas cup and is in sealing engagement with the housing. The gas cup and the fluid seal define a lubricant reservoir. The gas cup defines a lubricant passage for delivering a lubricant through the lubricant reservoir to lubricate the fluid seal.
It has long been recognized that the gas cup is slidably disposed in the housing of the fluid damper assembly to adjust for the volume change caused by the piston, thermal expansion of a damping fluid, and normal loss of the damping fluid. In addition, it is also known in the prior art that the gas cup of the fluid damper assembly includes fluid seals to provide separation between a high pressured gas contained in the gas chamber and damping fluid, e.g., hydraulic fluid, magnetorheological (MR) fluid, contained in the fluid chamber. However, the damping fluid, e.g., MR fluid, contains abrasive particles which causes premature wear to the fluid seals of the gas cup that ultimately lead to a premature failure of the fluid damper assembly.
Therefore it is desirable to reduce the premature wear of the fluid seals of the gas cup to thereby improve and extend the performance of the gas cup in the fluid damper assembly.